A file of signals intelligence reports, messages, and correspondence issued by the Government Code and Cypher School and sent by the head ('C') of the Secret Intelligence Service (MI6) to the Prime Minister, Winston Churchill. This file contains a covering note from C to the Prime Minister (PM) concerning the Foreign Secretary's comments (see 5389) on alleged Anglo-German peace talks, saying that he suspected that the Soviets may also have intercepted and read relevant Japanese diplomatic messages; and the PM asks C to draft a reply to Roosevelt.